Yuri Chernichuk, the plant's former chief engineer, said he had agreed to take the post because it was "in my opinion the only correct decision."

His appointment was confirmed by Moscow's Rosenergoatom, the Russian nuclear operator which has de facto managed the plant -- Europe's largest -- since its occupation by Russian forces.

In a statement on social media, Chernichuk said his priority was to "stay with our people at our plant, in our city and continue to fulfil my professional duty."

He praised the "bravery" of the plant's staff.

"We have done and are doing everything possible and impossible so that the world does not see a new Fukushima or Chernobyl," he added.

"This deserves unconditional recognition and great respect, not accusations of treachery."

He called on international organisations to "resolve the issue of the future and safe operation of the Zaporizhzhia plant exclusively through peaceful negotiations and civilised decisions."

Moscow's troops took control of the site on March 4.

Russia and Ukraine have for months mutually accused each other of shelling the plant.

The UN's atomic watchdog earlier this month denounced strikes on the plant, calling for a "stop to this madness."

Russian President Vladimir Putin had signed a degree to formally take over the plant in October.